Method and apparatus for detecting defects and embedded objects in sealed sterilized packaging

ABSTRACT

An inspection station identifies defects such as artifacts (e.g., dust, hair, particles) in the sealing areas of sealed sterile packages. A multi-head optical scanner can include at least two fiber optic sensors each comprised of a bundle of optical fibers arranged into a linear face coupled to an image processing module and oriented towards a scanning area of sealed packages moving through a conveyance system. An image processing module can analyze input from the at least two fiber optic sensor arrangements to identify artifacts in the sealing areas of the sealed packages.

INVENTION PRIORITY

The present invention claims priority of Provisional Patent ApplicationNo. 61/104,203, filed Oct. 9, 2008, entitled “method and apparatus fordetecting defects and embedded objects in sealed sterilized packaging,”which is hereby incorporated by reference.

TECHNICAL FIELD OF THE INVENTION

The embodiments of the invention are generally related to the field ofautomated packaging processes, and in particular, to sterilizedpackaging. More particularly, the embodiments of the invention arerelated to methods, systems and apparatuses for detecting defects andembedded object in sealed, sterilized packaging within an automatedsystem and process.

BACKGROUND OF THE INVENTION

The present invention relates to the quality control of the sealedsterile packaging process. Various micro objects (e.g., human hair,dust, injection molding debris, etc.) can become embedded betweensealing surfaces, which can compromise the sealing of sterile surgicalinstruments in a sterile package. It is desirable to automaticallyidentify defective package sealing products since the use of humanoperators to perform this task is costly and unreliable.

While the largest defects (discontinuities or voids) can be found usinga conventional optical inspection system such as that described in U.S.Pat. No. 6,097,427, issued Aug. 1, 2000, by taking an video image ofsealing areas, it is difficult to recognize micro defects or embeddedobjects with characteristic dimensions less than a hundred microns onlarge inspection areas during manufacturing process. Attempts toincrease magnification of the optical system to increase objectresolution will cause decreasing the camera field area resulting inimpractical images, long processing time, or complex visual systemsetups.

U.S. Pat. No. 5,155,790 issued Oct. 13, 1992, describes an electronicscanner or printer with fiber optic bundles. This system uses uniqueoptical fiber bundles for the optical subassembly to transfer images.The fiber bundle is organized so that first face (scanner) has a lineargeometry and the second face has area geometry. In the scannerconfiguration the fiber optic linear bundle transmits image pixels tothe face, which is then mechanically scanned into the video system andmemory for future image processing. The linear face comprises nominally5100 square fibers that covers up to 8.5 inches of a document with thefiber core diameter being about eight microns. Such a scanner, however,cannot be applied to the scan packaging area for several reasons: thescanning area is not flat and its scanning speed is too slow for realtime defects detection.

What is needed in the packaging art are improved methods and systems fordetecting defects and contamination (e.g., embedded objects) in sealed,sterilized packaging before it is shipped from packaging operations tocustomers.

SUMMARY OF THE PRESENT INVENTION

The following summary is provided to facilitate an understanding of someof the innovative features unique to the disclosed embodiment and is notintended to be a full description. A full appreciation of the variousaspects of the embodiments disclosed herein can be gained by taking theentire specification, claims, drawings, and abstract as a whole.

It is a feature of the present invention to enable improved qualitycontrol over sealed sterilized packaging process.

It is another feature of the present invention to provide systems andmethods that can obtain high resolution images at important regions(e.g., sealing paths) of packages and that is, therefore, simple toimplement and operate with low equipment costs (e.g., eliminating theneed of multiple cameras).

It is another feature of the present invention to use the multi-headfiber optical scanner for parallel image processing of all regions ofinterest during single frame capture of sampled packaging.

Accordingly, it is a feature of the present invention to utilize a setof linear fiber optic arrays distributed along the sealing paths of asterile package as the “scanned area”to dynamically acquire pixels at astacked linear array face. Each column (or row) provides a remoteoptical transmission of light illumination from the scanned area, whilethe whole stack produces a 2×d matrix for a whole set of fiber opticpixel image from the different locations on the package area. Thismethod provides highly effective, parallel image processing, and anoptimum procedure to scan sealing packaging areas using a singlehigh-resolution camera. As an additional feature, fiber optic sensorscan be oriented at certain angles over the scanning direction of apackage to cover larger detection width over the target package.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying figures, in which like reference numerals refer toidentical or functionally-similar elements throughout the separate viewsand which are incorporated in and form a part of the specification,further illustrate the present invention and, together with the detaileddescription of the invention, serve to explain the principles of thepresent invention.

FIG. 1 is a schematic diagram of fiber optical subassembly on thesealing area in accordance to the principles of this invention;

FIG. 2 is a schematic illustration of embedded object detection methodduring scanning of the sealing area by single linear array sensor forthree sequential video frames;

FIG. 3 is a plan view of six sealed sterile surgical packets in apackage frame and a block diagram of the vision and control systemsassociated with the present invention; and

FIG. 4 is a flow diagram of a method of inspecting sealed sterilepackaging for artifacts, in accordance with features of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The particular values and configurations discussed in these non-limitingexamples can be varied and are cited merely to illustrate at least oneembodiment and are not intended to limit the scope thereof.

FIG. 1 is a schematic illustration of the multi-head optical scanner 10employing fiber optic sensor arrangements 90 (e.g., an array) fortransmitting optical energy. Each sensor 95, 105 is comprised of bundleof optical fibers 100, 110 arranged in a linear face 90 oriented towardsa scanning area (or areas) of a package 20. As an example, the package20 illustrated in FIG. 1 includes a sterile area including a sealedpocket 40 defined by a border 30 and includes a sealing area 50. Sterileobjects (e.g., surgical tools) 70 are contained within the pocket 40.Input from the sensors 90 can be combined together into 2×D area face170. In the illustrated embodiment, the multi-head optical scanner isshown with only two stationary sensors 95, 105 that could perform a scanof the sealing area 50 when the package 20 is moving along axis 140along a package conveyance system (not shown); although it can beappreciated that more (or less) sensors can be employed, depending onthe application. The sensors 95,105 can be positioned at small 0.5 mm to1 mm focal distances from the sealing surface and can have about a 30degree angular position towards the direction of package motion to coverall width of a sealed pocket 40 defined by the sealing area 50. A fiberoptic bundle 100 can be operative to transmit pixels that representsealing surface illumination around the fiber cores. Signals from thesensor can be provided by the area face image processing module forprocessing and the identification of artifacts in the scanned areas. Acontroller coupled to the processing module can provide a control signalto identify a faulty package once artifacts in a sealing area 50 areidentified.

For illustration purpose only several types of defects are shown in thesealing area 50, but only two of them 80 and 120 can likely compromisethe sealed pocket's sealing. The other embedded objects 60 and 130 arenot likely to breach the seal because of their orientation and size,respectively. Each column 150, 160 within the 2×D structure of the areaface 170 represents pixel images from certain location of a targetpackage (in this case the sealing area 50) during the package's 20motion 140 (e.g., motion along an automated inspection line). The system10 and its method of use allow parallel image processing during packageinspection from multiple sensors during a single camera frameacquisition, which is a great advancement over the current state of theart.

FIG. 2 shows a schematic representation of the linear fiber optic sensorarrangement 90 used during image registration of embedded object 80 forthree sequential frames. For reliable pixels detection, diameter of thefiber core can ideally not exceed more than 25% of the characteristicsize of embedded object. In one test embodiment the 65 μm fiber core 95of 1×16 linear sensors is using to detect a human hair of 50 μm, thecore fibers being separated in array by 5 to 10 microns. Instantaneousobject 80 (e.g., a human hair) positions are shown during frametranslations 200 shown at moments in time T1, T2, and T3 duringsequential camera frames registrations. Positions are furtherrepresented by object spatial positions in FIG. 2 by references 82, 84,and 86. As can be seen the object registers first at fiber f2 (time markT1), then at fiber f8 (time mark T2), and finally f14 and f15 (time markT3). Time interval (T2−T1, or T3−T2) between object registrationsdepends on chosen camera frame rate that has to be high enough toprovide at least three frames per an embedded object registration inorder to reliably distinguish the object motion. First and second frameswill capture illumination from single fibers f2 and f8 while the thirdframe registers pixels in fibers f14 and f15 resulting in spatial pixelsdistance in fiber bundle 150 of 2×D area face that projected into cameraphotosensitive CCD. Pixel translations can be easily recognized duringimage processing, thus producing a signal to a PLC 280 to rejectcorresponding pocket 40 in the package 20.

FIG. 3 illustrates an embodiment of a system for detecting embeddedmicro objects in a sealing area of a sterile package. Illustrated forexemplary purposes is a frame 20 of six sealed sterile packages 40 beingprocessed through a defect inspection system 10. The system 10 includestwo set of linear optical sensors 200 and 270. The packages can beprovided in two rows (three per row) in a common frame 20. The first setof optical sensors can be positioned on a fixed bar where each sensor isaligned with the sealed areas 50 along the entire package frame 20. Asecond set of optical sensors can be mounted on a movable axis 270 thatprovides scanning of sealed areas 50 along a second direction 300, whichis shown in FIG. 3 as perpendicular to the motion of a conveyance system(not shown). Both sets of sensors 200, 270 provide complete sealed areapackage inspection. Accordingly, the first set performs defectsinspection while conveyer is at motion along direction 140 and thesecond set of sensors 270 can be activated the when conveyer is stoppedfor parts loading in upstream of conveyer.

Two sets of linear fiber optic sensors are combined into area face 150in an optical system 250 forming 2×D image of scanning areas betweensealed packages as shown in FIG. 3. Pixel images captured by the fiberface area can be coupled to a camera CCD chip 240 by fiber optic taper220. A fiber optic taper is an off-shelf optical component, which is acoherent fiber optic plate that transmits either a magnified or reducedimage from its input surface to its output surface. The output of theoptical system 250 can be connected to an image processing module 260,where frame-by-frame image analysis can be performed, either in realtime, or using set of buffered images, to search a pre-defined defectspattern. When defect has being detected by the image processing module260, a fault condition can be generated by a PLC 280. The faultcondition (a signal) from the PLC can be used to identify thecompromised package so that it can be removed or marked for rejection.As an example, the PLC 280 can send a signal downstream to the frameunload station to identify (mark) fault or to automatically separatedefective product from the good product.

Referring to FIG. 4, a flow diagram of a method of inspecting sealedsterile packaging for artifacts is illustrated. As shown in block 410,the method begins by optically capturing images of sealing areas onsealed sterile packages using a multi-head optical scanner including atleast two fiber optic sensors each comprised of bundle of optical fiberscoupled to an image processing module and oriented towards a scanningarea of sealed packages moving through a conveyance system. Block 420provides the step of processing images of sealing areas captured by themulti-head optical scanner to determine if the sealing areas containartifacts therein. Then Block 430 provides the step of identifyingsealing areas including sealing area locations wherein artifacts arelocated within sealed sterile packages.

It will be appreciated that variations of the above-disclosed and otherfeatures and functions, or alternatives thereof, may be desirablycombined into many other different systems or applications. Also thatvarious presently unforeseen or unanticipated alternatives,modifications, variations or improvements therein may be subsequentlymade by those skilled in the art which are also intended to beencompassed by the following claims.

The invention claimed is:
 1. An inspection station for opticallyinspecting sealed packages to identify artifacts in sealing areasdefining a boundary and inspection area of two sides and a top andbottom surrounding at least one sterile object contained within thesealed packages, comprising: a multi-head optical scanner including: afirst set of an at least two fiber optic sensor arrangement with eachset comprising more than one optical fiber from a bundle of opticalfibers arranged into a linear face and mounted on a conveyance system toacquire optical feedback of the sealing areas moving linearly in ay-direction that is parallel with movement of the conveyance system andthat are located on each of the two sides of the at least one sterileobject contained in sealed packages during movement of the conveyancesystem, and a second set of an at least two fiber optic sensorarrangement with each set comprising more than one optical fiber from abundle of optical fibers arranged into a linear face and mounted on amovable axis above the conveyance system to provide scanning of sealedareas along a x-direction that is perpendicular to the motion of theconveyance system and to acquire optical feedback of the sealing areasof the boundary and inspection area oriented in the x-direction withrespect to movement of the conveyance system, wherein boundary areas ofthe sealing areas targeted by the second set are located on top andbottom of the at least one sterile object contained in sealed packages,wherein the optical feedback is received from the sealing areas by thetwo sets of multi-head optical scanners as the sealed packages movethrough a conveyance system located beneath the multi-head opticalscanners; and an image processing module analyzing input from the twosets of at least two fiber optic sensor arrangements to identify whetherartifacts exist in the sealing areas of the sealed packages defining theboundary surrounding at least one sterile object contained within thesealed packages.
 2. The inspection station of claim 1, furthercomprising an area face combining input from the at least two fiberoptic sensor arrangements of each set into an array prior to providinginput from the at least two fiber optic sensors to the image processingmodule for analysis.
 3. The inspection station of claim 2, wherein saidarea face includes a 2×D area face combining input from the at least twofiber optic sensor arrangements into an array prior to providing theinput from the at least two fiber optic sensors to the image processingmodule for analysis.
 4. The inspection station of claim 3, furthercomprising a controller coupled to the image processing module toprovide a control signal identifying a faulty package once artifacts inthe sealing areas of a package are identified.
 5. The inspection stationof claim 3, further comprising a controller coupled to the imageprocessing module to provide a control signal identifying a faultypackage once artifacts in the sealing areas of a package are identified.6. The inspection station of claim 1, further comprising a controllercoupled to the image processing module to provide a control signalidentifying a faulty package once artifacts in the sealing areas of apackage are identified.
 7. A method of inspecting sealed sterilepackaging for artifacts trapped within sealed areas defining a boundaryincluding two sides and a top and bottom surrounding a sealed pocketcontaining at least one sterile article on the sealed sterile packaging,comprising: using a multi-head optical scanner to optically captureimages of sealing areas on sealed sterile packages traveling in ay-direction along a conveyance system using a first set of at least twofiber optic sensors each comprised of a bundle of optical fibers coupledto an image processing module and oriented towards a scanning arealocated at the sides of the sealed pocket of sealed packages to acquireoptical feedback from sealing areas defining a sealed pocket on thesealed packaged containing at least one sterile object, wherein theoptical feedback is received from the sealing areas by the multi-headoptical scanner as the sealed packages move through a conveyance system;using the multi-head optical scanner to optically capture images ofsealing areas on sealed sterile packages oriented in a x-directionperpendicular with travel of the conveyance system using a second set ofat least two fiver optic sensors mounted to a movable axis above theconveyance system and including, the at least two fiber optic sensors ofthe second set each comprised of a bundle of optical fibers coupled tothe image processing module and oriented towards a scanning area locatedat the top and bottom of the sealed pocket of sealed packages to acquireoptical feedback from sealing areas defining a sealed pocket on thesealed packaged containing at least one sterile object, wherein theoptical feedback is received from the sealing areas by the multi-headoptical scanner as the sealed packages move through a conveyance system;processing images of sealing areas captured by the multi-head opticalscanner to determine if the sealing areas contain artifacts therein; andidentifying sealed sterile packages including sealing area locations ofsealing areas thereon wherein artifacts are located.
 8. The method ofclaim 7, further comprising the step of providing a control signal whenartifacts are identified.
 9. The method of claim 7, wherein images ofsealing areas are captured by the multi-head optical scanner as thesealed sterile packages move along an axis of a package conveyancesystem.
 10. The method of claim 8, wherein images of sealing areas arecaptured by the multi-head optical scanner as the sealed sterilepackages move along an axis of a package conveyance system.
 11. Themethod of claim 9, further comprising the step of providing a controlsignal when artifacts are identified.